package likouJava;

public class 二叉树的最近公共祖先 {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if(root == null || root == p || root == q) {
            return root;
        }

        TreeNode left = lowestCommonAncestor(root.left, p, q);
        TreeNode right = lowestCommonAncestor(root.right, p, q);

        if(left != null && right != null){
            return root;  //p 和 q 分别在两边
        }
        return left != null ? left : right; //返回非空的一侧
    }

}
